Isolating switch of the pantograph type



G. T. TROLIN June 13, 1961 ISOLATING SWITCH OF THE PANTOGRAPH TYPE Filed. May 18, 1959 Fig/ INVENTOR Georg TTro Z (.11 BY Mk9 flromey United States Patent ISOLATING SWITCH OF THE PANTOGRAPH TYPE Georg T. Trolin, Vasteras, Sweden, assignor to Allmanna Svenska Elektriska Aktiebolaget, Vasteras, Sweden, a

Swedish corporation Filed May 18, 1959, Ser. No. 814,005 Claims priority, application Sweden May 21, 1958 1 Claim. (Cl. 200-48) In the construction of isolating switches of the pantograph type it is already known to use a switching arm similar to an overhead current collector for an electrical locomotive in which the arm is supported by stationary heads on two rotatable insulators. The lower levers of said current collector are thus mounted each on its own stationary head and are operated over a link or rod system by rotation of the insulators.

The present invention concerns an isolating switch, the arm of which is of the pantograph type and sup ported by two rotatable insulators, which are coupled together so that when rotated they move in the same direction. It is mainly characterised in that the operating levers of the pantograph with a displacement of half a revolution are eccentrically mounted each on its rotatable insulator.

The invention makes possible a simple operation of the switching arm, similar in design to a pantograph, without the use of a rod or link system, due to the operating levers of the pantograph not being mounted each on its stationary head but on supports which, when operated, describe arcs with the same radius around respective insulator axes, and also move in the same plane perpendicularly to these axes. Due to the supports being mounted each on its own insulator, with a displacement of half a revolution in relation to each other, the eifect is also obtained that the vertical centre line of the pantograph is not moved when the isolating switch is operated, but the pantograph arm moves, at closing, for instance, straight against the upper contact of the isolating switch and grips around this.

The accompanying drawing shows an embodiment of the invention. FIGURE 1 shows the isolating switch in closed position and FIGURE 2 in open position, seen in both cases from the side. FIGURE 3 is a schematic drawing of the isolating switch in an intermediate position seen from above.

The isolating switch consists of a base 1 on which a horizontal hollow cross bar 2 is placed, on the outer ends of which two insulators 3 and 4 are rotatably supported.

These insulators are, at the lower end, mechanically 2,988,151 1 Patented June 13, 1961 coupled together by a wire running through the hollow cross bar 2 and thus not seen in the figure, so that, when rotated, they describe equally large angles in the same direction. The isolating switch is operated by a rod 5 attached to the insulator 4, which at its lower end is provided with a handle 6. The insulators are at the upper end connected with each other by a rod 9. Furthermore, each insulator is at its upper end provided with an arm 7 and 8 respectively. These arms are, at one end, attached each to its own insulator, with a displacement of half a revolution in relation to each other, and their axes lie in a plane perpendicular to the axes of the insulators. In the other end of the arms 7 and 8, the bolts 10 and 11 are pivoted, with their axes parallel to, and at the same distance from, the respective insulator axis. The two operating levers 14 and 15 of the pantograph arm 17 are pivotally mounted each on its own bolt, on the axes 12 and 13 which are fastened in the bolts perpendicularly to the axes of the bolts. The overhead contact of the isolating switch is designated 16.

The closing of the isolating switch is carried out by turning the rod 5, and consequently the insulators 3 and 4 with the arms 7 and 8 mounted thereon, half a revolution. Thereby the operating levers 14 and 15 of the pantograph are moved against each other, the pantograph then being raised and gripping around the stationary overhead contact 16. To open, the rod 5 is turned equally far in the opposite direction. From FIGURE 3 it is obvious that, as already mentioned, the centre line of the pantograph is not moved when operating the isolating switch.

Iclaim:

Isolating switch, comprising two rotatable insulators, means coupling the insulators so that when rotated they describe the same angles in the same direction, operating levers, displaced half a revolution in relation to each other, eccentrically mounted each on one of said rotatable insulators for rotation therewith, a pantograph structure having arms pivoted to each of said levers, and a switch contact carried by said pantograph structure, the lower ends of each of the operating levers, when the pantograph switch is operated, being rotated around the axis of the respective supporting insulator therefor.

References Cited in the file of this patent UNITED STATES PATENTS 2,510,051 De Montmollin et a1. June 6, 1950 2,748,211 Butz May 29, 1956 2,781,426 Lardelli Feb. 12, 1957 FOREIGN PATENTS 932,076 Germany Aug. 22, 1955 

